A Dog's Purpose received mainly negative reviews from the critics, and I'm not sure why. I found that the movie delivered exactly what was promised. If you love dogs, you'll most likely love this movie. Even as a cat lover, I found myself getting into it.
Bailey-Bailey-Bailey-Bailey-Bailey is a dog who experiences several lives, only to reincarnate over and over, touching the lives of several different sets of humans.
Overall, the movie is done well. It's light-hearted. The dog voice-over is actually funny--especially when it's obvious that a dog actor decides to do his own thing. The human stories are touching and believable.
As such, I can see exactly why most user ratings of the movie are positive. If you go to see a movie because of what it promises, and if it delivers, you're going to enjoy it, despite what those uppity critics say. (Remember, they have to give bad reviews to prove their own existence.)
I haven't read any of the negative reviews, but if I had to guess, it may be that some human characters disappear without any resolution (just like normal life?). Or perhaps it was missing all kinds of cussing, action scenes, and the typical Hollywood formula.
I will give one major complaint, though. The trailers I saw basically give away the ending, so when it was over, I was underwhelmed. I'm pretty sure I would have enjoyed it more had I not known what was coming. Even today, looking for a good trailer to post with this, I could only find this one 15-second trailer that doesn't spoil the ending. Perhaps this unforgivable sin is really why the critics gave bad reviews.
So, stay away from the trailers, and once this hits DVD, Netflix, or Hulu, check it out. It's the perfect family rent movie.